Motor fuel composition

ABSTRACT

MOTOR FUEL COMPOSITION COMPRISING A MIXTURE OF HYDROCARBONS IN THE GASOLINE BOILING IN THE GASOLINE BOILING RANGE CONTAINING (1) THE SALT REACTION PRODUCT OF (A) A PARAFFINIC OIL OXIDATE HAVING A NEUTRALIZATION NUMBER BETWEEN 55 AND 80 AND A SAPONIFICATION NUMBER BETWEEN 100 AND 200, AND (B) AN AMIDE HAVING THE FORMULA   R&#34;-NH-CH2-CH2-CH2-N(-R&#39;&#39;)-CO-R   IN WHICH R IS A MONOUNSATURATED HYDROCARBYL RADICAL HAVING FROM 16 TO 18 CARBON ATOMS AND R&#39;&#39; AND R&#34; ALTERNATELY REPRESENT HYDROGEN AND A HYDROCARBYL RADICAL HAVING 14 TO 18 CARBON ATOMS, AND (2) A NORMALLY LIQUID AMINE SALT OF BRANCHED CHAIN PRIMARY ALKYL ACID ESTERS OF ORTHOPHOSPHORIC ACID IN WHICH EACH ESTERIFYING GROUP CONTAINS 13 TO 16 CARBON ATOMS AND THE AMINE IS AN ALIPHATIC HYDROCARBON MONOAMINE OF 6 TO 24 CARBON ATOMS IN WHICH EACH ALIPHATIC HYDROCARBON RADICAL IS ATTACHED TO THE NITROGEN THROUGH A SATURATED CARBON ATOM.

United States Patent 3,704,109 MOTOR FUEL COMPOSITION Stanley R. Newman, Fishkill, Ronald W. Von Allmen, Hopewell Junction, and Kenneth L. Dille and Herbert E. Vermillion, Wappingers Falls, N.Y., assignors to Texaco Inc., New York, N.Y. No Drawing. Filed Dec. 20, 1968, Ser. No. 785,774 Int. Cl. C101 1/26 US. Cl. 44-66 6 Claims ABSTRACT OF THE 7 DISCLOSURE Motor fuel composition comprising a mixture of hydrocarbons in the gasoline boiling in the gasoline boiling range containing (1) the salt reaction product of (A) a paraffinic oil oxidate having a neutralization number between 55 and 80 and a saponification number between 100 and 200, and (B) an amide having the formula in which R is a monounsaturated hydrocarbyl radical having from 16 to 18 carbon atoms and R and R alternately represent hydrogen and a hydrocarbyl radical having 14 to 18 carbon atoms, and (2) a normally liquid amine salt of branched chain primary alkyl acid esters of orthophosphoric acid in which each esterifying group contains 13 to 16 carbon atoms and the amine is an aliphatic hydrocarbon monoamine of 6 to 24 carbon atoms in which each aliphatic hydrocarbon radical is attached to the nitrogen through a saturated carbon atom.

This invention relates to an improved motor fuel composition for internal combustion engines. More particularly, the invention involves the discovery that the incorporation of a combination of additives in gasoline, namely a minor amount of the salt reaction product of a liquid oxidate and an amide and an amine salt of an alkyl acid phosphate produces a fuel having outstanding carburetor detergent properties in addition to good corrosion inhibiting, anti-icing and anti-wear properties.

Modern internal combustion engine design is undergoing important changes to meet certain standards concerning engine and exhaust gas emissions. A major change in engine design presently being widely adopted is the feeding of blow-by gases from the crankcase zone of the engine into the intake air supply to the carburetor rather than venting these gases to the atmosphere as in the past. These blow-by gases contain substantial amounts of depositforming substances and it has been observed that some of the substances in the blow-by gases form deposits in and around the throttle plate area of the carburetor. The deposits restrict the flow of air through the carburetor at idle and low speeds so that an overrich fuel mixture results. This condition produces rough idling, engine stalling and also results in excessive hydrocarbon exhaust emissions to the atmosphere. In addition to overcoming the foregoing problem, a competitive modern gasoline must provide a high level of corrosion inhibiting, anti-icing and anti-wear properties.

A novel fuel composition has been discovered which mitigates or overcomes the problem of deposit laydown in the carburetor of an internal combustion engine. More specifically, a motor fuel composition containing a novel additive combination has been found which is very effective for substantially reducing the laydown of deposits in a carburetor. When this gasoline is employed using a carburetor in which a substantial buildup of deposits has already taken place from prior use, the motor fuel of the 3,704,109 Patented Nov. 28, 1972 invention is effective for removing a substantial amount of the deposits in the carburetor. The additive combination also provides excellent corrosion inhibiting, anti-icing, and anti-wear properties in the gasoline.

The motor fuel composition of the invention comprises a mixture of hydrocarbons in the gasoline boiling range and minor amounts of (1) the salt reaction product of:

(A) an oxidate having a neutralization number between 55 and and a saponification number between and 200 derived from a paraflinic lubricating oil, and

(B) an amide represented by the formula:

in which R is a monounsaturated hydrocarbyl radical having from 16 to 18 carbon atoms, and R and R" alternately represent a member of the group consisting of hydrogen and a hydrocarbyl radical having from 14 to 18 carbon atoms, and (2) a normally liquid amine salt of branched chain primary alkyl acid esters of orthophosphoric acid in which each esterifying group contains 13 to 16 carbon atoms and the amine is an aliphatic hydrocarbon monoamine of 6 to 24 carbon atoms in which each aliphatic hydrocarbon radical is attached to the nitrogen through a saturated carbon atom.

The liquid oxidate having a neutralization number between 55 and 80 and a saponification number between 100 and 200 employed to form the salt reaction product is derived from a parafiinic lubricating oil. This paraffinic oil oxidate preferably has a neutralization number between 60 and 80, a saponification number between and 165, an unsaponifiable content less than about 55 percent, a viscosity less than 100 SUS at 210 F., and a Lovibond /2" cell color rating of less than 100. It is obtained by air oxidation of a refined paraifinic base lubricating oil having a viscosity between and SUS at 100 F., a pour point less than 5 F., a color rating of less than 10 and an aniline point between 214 and 225 F. It is convenient to employ the liquid oxidate in solution in a light distillate mineral lubricating oil to facilitate handling and to provide a medium for forming the salt.

The amide employed to form the reaction product of the invention is represented by the formula:

in which R is a monounsaturated hydrocarbyl radical having from 16 to 18 carbon atoms, preferably a radical derived from oleic acid, and R and R" alternately represent a member from the group consisting of (1) hydrogen and (2) a hydrocarbyl radical having from 14 to 18 carbon atoms. Preferably R and R" alternately represent a member from the group consisting of (1) hydrogen and (2) an unsaturated hydrocarbyl radical having 18 carbon atoms derived from oleic acid. The definition of the values of R and R" as alternately representing the specified members means that when R is hydrogen R" is a hydrocarbyl radical and vice versa. Amide mixtures conforming to the above formula are available commercially. For example, the reaction product of N-oleyl 1,3-diaminopropane with oleic acid to form an amide of the noted type is commercially available.

The salt reaction product is obtained by admixing, preferably in a solvent, suitable amounts of the parafiinic lubricating oil oxidate and the above-defined amide. In general, the liquid oxidate and the amide are combined in proportions ranging from about 2:1 to 5:1 respectively, preferably in the proportion of 3.6:1. The formation of the salt involving reaction between the acid groups in the oxidate and the amine groups in the amide occurs spontaneously although complete salt formation generally requires a moderate amount of time. Formation of the salt may be speeded up by applying heat to the reactants. Alternatively, formation of the salt reaction product may be effected by adding the two components of the reaction product to a gasoline composition and permitting the reaction to take place in situ in the fuel. This reaction product and a motor fuel containing same are the subject of a commonly assigned copending patent application, Ser. No. 559,735 filed on June 23, 1966, now abandoned.

The oxidate-amide salt reaction product is employed in gasoline in a concentration ranging from about 0.001 to 0.05 weight percent of the gasoline. The preferred concentration of the salt reaction product is from about 0.005 to 0.01 weight percent, amounts ranging from about 13 to 30 p.t.b. (pounds per thousand barrels) of gasoline.

The amine salts of this invention may be prepared according to any of the methods of the art, by completely or partially neutralizing primary alkyl acid phosphates, wherein the primary alkyl groups have from 13 to 16 carbon atoms, in branched chain configuration, with aliphatic hydrocarbon monoamines containing a total of from 6 to 24 carbon atoms.

The branched chain in primary alkyl acid esters of orthophosphoric acid (acid phosphates) are those esters in which only 1 or 2 of the three acidic hydrogen atoms of orthophosphoric acid have been replaced by the alkyl groups, i.e. the monoalkyl dihydrogen phosphates and the dialkyl hydrogen phosphates. Such esters may be obtained by reacting an alcohol with phosphorus pentoxide (P From about 2 to about 4 moles of the alcohol are used per mole of P 0 Preferably about 3 moles of the alcohol per mole of P 0 are used to yield approximately equi-molar mixtures of the monoand dialkyl esters of orthophosphoric acid, containing about 40 to about 60 mole percent of the monoalkyl esters and about 60 to about 40 mole percent of the dialkyl esters. These mixtures of monoand dialkyl esters are preferred for reasons of economy but other mixtures, as well as the single monoalkyl esters and single dialkyl esters, may also be used.

The amines that are used to produce the novel salts of this invention are the aliphatic hydrocarbon monoamines containing a total of 6 to 24 carbon atoms in which each aliphatic hydrocarbon radical is attached to the nitrogen through a saturated carbon atom. The term aliphatic hydrocarbon monoamine will be understood to mean a compound which contains only one amino nitrogen to which is attached 1 to 3 aliphatic hydrocarbon radicals. Thus, the amines may be primary, secondary,

or tertiary amines, with the primary amines usually being preferred. The aliphatic hydrocarbon radicals attached to the nitrogen may be acyclic (open, chain) or alicyclic (cycloaliphatic) radicals. Also, the aliphatic hydrocarbon radical may be a saturated or unsaturated radical provided that the carbon atom which is attached to the nitrogen atom is a saturated carbon atom, that is, a carbon atom that is not attached to another carbon or to the nitrogen by a multiple bond. Preferably, the amine will be an alkyl (acyclic, saturated) monoamine of 6 to 24 carbon atoms and most preferably of 8 to 18 carbon atoms. Also, preferably, when the amine is a secondary amine, it will contain a total of at least 8 carbon atoms and, when it is a tertiary amine, it will contain a total of at least 10 carbon atoms.

Examples of suitable amines are: hexylamine; cyclohexylamine; octylamine; Z-ethylhexylamine; laurylamine; hexadecylamine; t-dodecylamine; mixed t-alkyl primary amine fractions having from 12 to 21 carbon atoms, a mixture of stearyl, palmityl and oleyl amines, di-n-butylamine, di-sec-butylamine, diisobutylamine, diamylamine, di-2-ethylhexylamine, diisooctylamine, dilaurylamine, dicyclohexylamine, tributylamine, trihexylamine, triisooctylamine, N,N diethylcyclohexylamine, N,N dimethylstearylamine, and N,N-dimethyloleylamine.

Any of the above amines may be employed in salt formation with any of the above branched chain alkyl acid phosphates. Preferred, however, are 2-ethylhexylamine, t-dodecylamine, cocoamine, the mixed t-alkyl primary amine fractions containing 12 to 14 carbon atoms, t-octylamine and t-nonylamine. These salts are generally employed in a concentration ranging from about 0.001 to 0.10 percent with the preferred range being from about 0.003 to 0.03 weight percent. The foregoing amine salts are disclosed in U.S. 3,228,758.

The following example illustrates the preparation of the oxidate-amide reaction product. In this example, a liquid oxidate was employed as a solution in a light distillate mineral lubricating oil having an SUS viscosity at 100 F. of about 100. The mixture or solution consisted of parts by weight of light distillate mineral lubricating oil and 25 parts by weight of liquid oxidate.

EXAMPLE I 5.0 pounds of the mixture of amides, produced by reacting N-oleyl 1,3-diaminopropane with oleic acid in a 1 to 1 proportion, represented by the formula:

in which R and R" alternately represent a member from the group consisting of hydrogen and the oleyl radical, and 18.0 pounds of a liquid oxidate having a neutralization number about 70 and a saponification number about 142 dissolved in 54 pounds of light distillate mineral lubrieating oil were thoroughly admixed. The salt reaction product of the amide formed in situ in the lubricating oil carrier.

The carburetor detergency effect of the motor fuel of the invention is determined in two phases or aspects of the detergency test. The test designated the Chevrolet V-8 Carburetor Detergency Test, is run in a specially modified engine. This test employs a Chevrolet V-8 engine equipped with a four barrel carburetor mounted on a test stand. The two secondary barrels of the carburetor are sealed and each of the primary barrels modified so that an additive fuel can be run in one barrel and a base fuel run in the other. The primary carburetor barrels were previously modified so that they had removable aluminum inserts in the throttle plate area in order that deposits formed in this area could be conveniently weighed.

In the procedure designed to determine the effectiveness of the detergent-containing fuel for preventing the laydown of deposits (Phase I), the engine is run for a period of 24 to 48 hours with the base fuel being fed to one barrel and the additive fuel to the other barrel while engine blowby is circulated to the air inlet of the carburetor. After the run, the inserts are removed from the carburetor and weighed to determine the difference between the performance of the additive and non-additive fuels. The aluminum inserts are then cleansed, replaced in the carburetor and the process repeated with the fuels reversed in the carburetor barrels to minimize differences in fuel distribution and barrel construction. The deposit weights in the two runs are averaged and the detergency effectiveness of the additive fuel expressed in percent.

In the procedure designed to determine the effectiveness of an additive fuel to remove preformed deposits, known as Phase II, the engine is run for a period of time usually 24 or 48 hours using the base fuel in both barrels with engine blow-by circulated to the air inlet of the carburetor. The weight of the deposit on both sleeves is determined and recorded. The engine is then cycled for 24 additional hours, with base fuel fed to one barrel and additive fuel fed to the other and no blow-by fed to the carburetor. The inserts are then removed from the carburetor and weighed to determine the difference between the performance of the additive and non-additive fuels in removing the preformed deposits. After the aluminum inserts are cleaned, they are replaced in the carburetor and the process repeated with the fuels reversed in the carburetor barrels to minimize differences in fuel distribution and barrel construction. The deposit weights in the two runs are averaged and the effectiveness of the base fuel and of the additive fuel for removing deposits expressed in percent. A minor amount of a light distillate mineral oil introduced in the fuel as the carrier component of an additive has no effect in the two phases of the test.

The base fuel employed in the following examples was a premium grade gasoline having an octane research number of about 100.1 containing 2.78 gms. of tetramethyl lead per gallon. This gasoline consisted of about 38% aromatic hydrocarbons, 8% olefinic hydrocarbons and 54.0% paraffinic hydrocarbons and boiled in the range from about 86 'F. to 366 F.

EXAMPLE II A gasoline blend was prepared consisting of the above base fuel containing 23 p.t.b. (pounds per thousand barrels of gasoline) of the oxidate-amide salt reaction product of Example I and p.t.b. of the 2-ethylhexyl amine salt of monoand di-tridecyl acid phosphate. The base fuel and the additive-containing gasoline blend were tested and compared for their carburetor detergency properties in the above-described Chevrolet V-8 Carburetor Detergency Test.

'In Phase I of this test, the gasoline blend containing the additive combination was 40 percent more effective than the base gasoline in preventing the build-up of deposits in the carburetor.

In Phase II of this test wherein the fuel composition is tested for its effectiveness for removing preformed deposits from the carburetor, the gasoline blend containing the additive combination removed 77 percent of the preformed deposits from the carburetor. In both aspects of this test, there was a substantial improvement in the additive-containing gasoline blend over the base fuel.

The anti-icing properties of the additive-containing fuel of the invention was determined in a carburetor icing demonstrator apparatus consisting of a vacuum pump equipped so that cool, moisture-saturated air from an ice tower is drawn through a. simple glass tube gasoline carburetor. The gasoline sample is placed in a sample bottle and is drawn into the glass carburetor through a 20 gauge hypodermic needle. Evaporation of the gasoline in the gas tube further cools the cold, moist air with resulting ice formation on the throttle plate. The formation of ice on the throttle plate causes an engine to stall and it has been found that this condition is equivalent to a pressure drop across the throttle plate of about 0.5 inch of mercury and the time required to reach this pressure drop is noted. The vacuum pump is adjusted to give a vacuum of 1.8 inches mercury and the test is run until either a pressure of 2.3 inches mercury has been reached or the run has continued for 300 seconds. Since with most fuels this pressure drop is reached in 1 to 4 minutes, 300 seconds is the maximum time for a run. A fuel composition which provides a minimum of 200 seconds run in this test is an effective carburetor anti-icing fuel composition.

EXAMPLE III The base fuel and the gasoline blend described in Example II above were tested for the carburetor anti-icing properties. The results are given in Table I below.

Table I.-Anti-Icing Test Fuel composition: Stalling time, seconds (1) Base fuel 57 (2) Gasoline blend (Example II) 229 This test shows that a gasoline containing the additive combination of the invention is a highly effective antiicing fuel composition.

6 EXAMPLE IV TABLE II.-EXHAUST EMISSIONS 1967 CORTINA Initial Final Base f el:

05 hydrocarbons, p.p.m 350 1, 350 C0, percent 4. 52 7.67 Gasoline blend:

Cs hydrocarbons, p.p.m 384 880 00, percent 4. 87 4. 90

This example shows that the gasoline blend of the invention maintained a low level of carbon monoxide emissions for the entire test period and also gave a much lower level of C hydrocarbon emissions at the end of the test run.

EXAMPLE V The effect of the additive-containing fuel of the invention on engine wear was determined in a High Speed Road Test using six matched Opel Rekord automobiles. The cars on which the wear test was conducted were run at an average speed of miles per hour for 12,000 miles. The wear was determined by weighing the top compression ring from four cylinders both before and after the road test from all of the cars. Three cars were run on the base fuel and three on the additive combination.

The base fuel in this example was a premium quality gasoline boiling from 29 C. to 200 C. with a 50% boiling point of 102 C. This fuel consisted of 44 percent aromatic hydrocarbons, 14 percent olefins and 42 percent paraflins. This fuel contained 0.049 volume percent of tetraethyl lead and had an R.O.N. of 99.8.

The additive containing gasoline blend of the invention consisted of the base fuel containing 23 p.t.b. of the oxidate-amide salt reaction product of Example I and 10 p.t.b. of the 2-ethylhexyl amine salt of monoand ditridecyl acid phosphate.

The average ring weight loss for the twelve compression rings in the three cars run on the base fuel was 119.8 milligrams per ring. The average ring weight loss for the twelve compression rings in the three cars run on the additive containing fuel was 92.9 milligrams per ring. The difference or 26.9 milligrams average per ring less wear for the cars burning the additive-containing fuel indicates that there was a substantial improvement in the anti-wear properties of this fuel due to the additive combination.

Obviously, many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. A motor fuel composition effective for maintaining a low level of carbon monoxide and C hydrocarbon exhaust emissions comprising a mixture of hydrocarbons in the gasoline boiling range containing 0.001 to 0.05 weight percent of (1) the salt reaction product of (A) a parafiinic oil oxidate having a neutralization number between 55 and and a saponification number between and 200 derived from a paraffinic lubricating oil, and

(B) an amide represented by the formula:

8 in which R is a monounsaturated hydrocarbyl 6. A composition according to claim 1 in which said radical having from 16 to 18 carbon atoms and normally liquid amine salt of orthophosphoric acid is the R and R alternately represent a member from Z-ethylhexyl amine salt of monoand ditridecyl acid the group consisting of hydrogen and a hydrophosphate. carbyl radical having from 14 to 18 carbon 5 References Cited atoms, and 0.001 to 0.10 weight percent of:

D (2) a normally liquid amine salt of branched chain UNITE STATES PATENTS rimary alk 1 acid esters of ortho hos horic acid in 2598213 5/1952 44*71 svhich each esterifying group cont ains B to 16 car- 3036903 5/1962 Klrkwood et a1 44*66 bon atoms and the amine is an aliphatic hydrocarbon l0 3228758 1/1966 Bauer 252-392 monoamine of 8 to 18 carbon atoms in which each 28335334 5/1958 m 44-70 aliphatic hydrocarbon radical is attached to the ni- 2922707 1/1960 Lmdtmm et a1 44 71 trogen through a saturated carbon atom. 325 25 a1 2. A composition according to claim 1 in which said 3,460,923 8/1969 Dorer 44 72 salt reaction product is obtained by reacting 2 to 5 parts 15 of said liquid oxidate with 1 part of said amide.

3. A composition according to claim 1 in which said DANIEL WYMAN Pnmary Exammer salt reaction product is obtained from a liquid oxidate Y H SMITH Assistant Examiner having a neutralization number about 70 and a saponification number about 142. 20

4. A composition according to claim 1 in which said amide is N-oleyl 1,3-diaminopropane. 44 DIG 1, 1 4, 71; 252 392 5. A composition according to claim 1 in which said amine is a primary alkylamine having from 8 to 18 carbon atoms. 

